A 1 500kg satellite is in orbit 250km above earth's surface.

1. The problem statement, all variables and given/known data
A 1 500kg satellite is in orbit 250km above earth's surface. What minimum additional energy is needed to place this satellite in a new stable orbit 800km above earth's surface?

2. Relevant equations
W = delta Ep = -GMm(1/r2-1/r1)

Ep = -GMm/r
Ek = GMm/2r or 1/2mv^23. The attempt at a solution
I tried using the work formula = -GMm (1/2r2-1/2r1, but I get the wrong answer. The answer is 3.41 x 10^9J. I thought to change the radius of orbit from one to another is the change in potential energy which is work?

For instance, in this question "An unpowered 1600kg object has an upward velocity of 7.0x10^3 m/s at an altitude of 100km above the earth. The object reaches a maximum altitude of 400km" would there be a kinetic energy change?

For instance, in this question "An unpowered 1600kg object has an upward velocity of 7.0x10^3 m/s at an altitude of 100km above the earth. The object reaches a maximum altitude of 400km" would there be a kinetic energy change?

Yes. There is a change in kinetic energy if there is a change in speed. What is the speed at maximum altitude?

However, you need to be careful with questions that ask you to calculate work. In particular, there is a difference between asking how much work you would have to do as compared to how much work the force of gravity does.

The work done by the force of gravity is always equal to the negative of the change in potential energy only. (Any change in kinetic energy is irrelevant.)